1. Field of the Invention
The present invention relates to accelerator pedal devices for a wheeled motor vehicle, and more particularly to accelerator pedal devices of a type which is constructed to accurately operate switches incorporated therewith.
2. Description of the Prior Art
In automatic transmission motor vehicles of a type equipped with an electromagnetic clutch, there are usually installed near the accelerator pedal a clutch control switch and a pedal depression degree sensing switch. The clutch control switch senses a depression of the accelerator pedal for controlling the ON-OFF operation of the electromagnetic clutch and the pedal depression degree senses a depression degree of the accelerator pedal for changing the gear speeds of the automatic transmission.
One accelerator pedal devices of the above-mentioned type is shown in, for example, Japanese Utility Model Second Provisional Publication No. 59-21057. In this conventional pedal device, a pedal lever (viz., accelerator pedal proper) and an auxiliary lever are arranged to pivot about a common axis. The auxiliary lever has an upper end fixed to an accelerator cable, so that the pivotal movement of the auxiliary lever induces an axial movement of the accelerator cable to control the engine speed. A so-called "lost motion mechanism" is further arranged between the pedal lever and the auxiliary lever so that the pivotal movement of the auxiliary lever commences only when the pedal lever is depressed to pivot by a given angle relative to the auxiliary lever. A clutch control switch is incorporated with the lost motion mechanism, so that the ON operation of the clutch control switch is always effected prior to the opening movement of a throttle valve of the engine.
However, due to its inherent construction, the above-mentioned accelerator pedal device has the following drawback.
That is, due to a remarkable tensile force inevitably produced in the accelerator cable during the depression of the pedal lever, it is very difficult to obtain a highly timed operation of the clutch control switch with respect to the pivotal movement of the pedal lever. Thus, usually, a complicated adjusting mechanism is further employed for dealing with such drawback. However, employment of such a adjusting mechanism induces not only a complicated construction of the device but also increased production cost of the same.